why do we create genres (music, movies, books)

And in particular, is there any statistical mechanics type explanation?
In music, we like to group songs into types
- Pop, rock, country, R&B
[?] What will ChatGPT do to it?
- It should allow us to get more personalized recommendations.
What are things that seem analogous?
- research areas
What are the dynamics? Aka what the physics of genres
- [?] What determines the distribution of genres?
  - E.g. how many "big" genres can there be?
    - Maybe one factor is how easy it is for people to discover new music.
    - Things like spotify can have a homogenizing effect, because it recommends popular music. But it could also have a spreading out effect, because it gives ability to discover new music.
      - [?] What determines the ultimate effect?
- [?] How do new genres get created?
  - Is it because of just one person?
  - What makes a time ripe for genre creation?
  - Maybe good to understand some examples
- [?] How do genres die?
- Why should there be genres?
- Forces
  - social cohesion
    - friends recommend songs; and songs are also a character trait with which people make friends
  - innovation
  - discovery platforms